This R-01 grant proposal is a response to PA-14-112 A Family-Centered Self-Management of Chronic Conditions. The project (a) evaluates four culturally adapted, family-based treatments designed to improve health status, self-management behaviors and self-efficacy among Mexican-Americans with Type 2 diabetes using a Sequential, Multiple Assignment Randomized Trial in a public health setting, and (b) tests hypotheses about the applicability of Ryan and Sawin's Individual and Family Self-Management Theory, the conceptual foundation for the intervention's key constructs, to the study of diabetes self-management in this population. This conceptual model was selected for study because its emphasis on the integration of family members as partners in care while promoting illness self-management is highly germane to the study population and to the proposed intervention. Spanish speaking, Mexican-American patients with Type 2 diabetes and their families will be recruited from a primary care clinic affiliated with a large, urban public hospital located in a predominantly Mexican American area of Los Angeles. In the first phase of the study, subjects will be randomly assigned to six 2.5 hour sessions (three months) of either: 1) Tomando Control de su Diabetes (TC), a culturally tailored, community-based, Diabetes Self-Management program delivered in a group format by community health workers (promotoras) working with individual patients and families; or 2) TC delivered by health professionals (licensed nurses). Evaluations will be made at baseline, three months, six months and 12 months. After six weeks of treatment (at the midway point of the intervention), subjects will be assessed for improvement in diabetes self-management behaviors (the primary outcome). In the second phase of the study, those subjects who have improved their diabetes self-management behaviors by 50% over baseline will be continued in their assigned treatment for the duration of three months. Those subjects who do not meet this target will be re-randomized to receive either: 1) an augmented version of TC that has a specific focus on engaging family members; or 2) a multifamily group treatment led by nurses specially trained in teaching diabetes self-management skills for an additional three months. Subjects will be assessed on setting and adhering to self-management goals related to diabetes; self-management behaviors including adhering to the ADA diet, engaging in exercise activities, monitoring glucose levels and taking prescribed hypoglycemic medications; diabetes self-efficacy; and hemoglobin A1c levels. Family members will be assessed during these same time frames to determine their knowledge of diabetes care; levels of collaborative goal setting with their ill relative and the health care provider; and levels of family support. The results will advance the understanding of the factors that affect self-management for Mexican-Americans with Type 2 diabetes, and will provide valuable information towards constructing an adaptive intervention that will help to determine which treatment strategies work to improve diabetes self-management behaviors most efficiently and for whom.